Horton, doubled over in pain, skated to the bench. He retreated to the dressing room and never returned. Seguin took over most of Horton’s shifts on the first line.

His injury came after the Bruins had a glittering chance to win. Chicago was called for too many men at 12:08. On the power play, Corey Crawford stuffed David Krejci. Horton was on the doorstep for the rebound, but couldn’t elevate his shot over Crawford.

Horton (zero shots, 22:28 of ice time) missed the last five regular-season games because of an upper-body injury suffered in a fight with Jarome Iginla.

Horton had an assist on Milan Lucic’s first-period goal. But Horton was stripped prior to Brandon Saad’s goal in the second period. Horton had the puck along the wall in the defensive zone. Marian Hossa picked Horton’s pocket from behind to trigger the attack the other way. Hossa set up Saad, who beat Rask at 3:08 of the second to make it a 2-1 game.

If Horton is unable to play in Game 2, Jordan Caron could draw into the lineup.